For Researchers

How to request access to NCI-IDD datasets and survey tools

The National Association of State Directors of Developmental Disabilities Services (NASDDDS) and Human Services Research Institute (HSRI), as collaborators on the National Core Indicators-Intellectual and Developmental Disabilities (NCI-IDD), engage in research activities, projects and studies to generate knowledge and information of relevance to state agency officials. Projects are completed by NCI-IDD staff and may be performed in collaboration with NCI-IDD member states.

In addition, research using NCI-IDD data and materials may be conducted by approved universities, governmental agencies and private organizations. Research activities must be consistent with the NCI-IDD mission, goals and guiding principles, model positive practice and steer decision-making toward areas of exploration that: (a) are relevant to the lives of people with intellectual and developmental disabilities, (b) demonstrate respect for the independence and individuality of people receiving support, (c) result in the development of practical information and instrumentation that can be used by member state agency officials to improve services and supports for all people with disabilities, and (d) contribute to the quality of the knowledgebase on community supports furnished to people with developmental disabilities.

It is the policy of HSRI and NASDDDS to encourage research that generates empirically sound knowledge and evidence with the potential of improving the quality and outcomes of services furnished to individuals with developmental disabilities by publicly financed service delivery systems. The policies and procedures related to sharing NCI-IDD data and materials seek to promote the investigation of issues that lead to improvements in the lives of individuals with developmental disabilities while safeguarding each person’s right to privacy, confidentiality and the protection of personal information.

To request use of the NCI-IDD materials and/or datasets, researchers must review documented policies and procedures and complete a request and use agreement.

For more information, please contact us.

List of selected research articles that use NCI-IDD data

Isvan, N., Bonardi, A., & Hiersteiner, D. (2023). Effects of person-centred planning and practices on the health and well-being of adults with intellectual and developmental disabilities: a multilevel analysis of linked administrative and survey data. Journal of Intellectual Disability Research, doi: 10.1111/jir. 13015.

Bradley, V. J., Hiersteiner, D. (2022) Quality monitoring of intellectual and developmental disabilities systems in the US: Assessing the utility and applicability of selected National Core Indicators to national and state priorities, Front. Rehabil. Sci., Vol. 3.

Bradley, Valerie J.; Hiersteiner, Dorothy; Li, Henan; Bonardi, Alexandra; and Vegas, Laura (2020) “What Do NCI Data Tell Us About the Characteristics and Outcomes of Older Adults with IDD?,” Developmental Disabilities Network Journal: Vol. 1 : Iss. 1 , Article 6. Available at:

Bradley, V., Hiersteiner, D., Rotholz, D., Maloney, J., Li, H., Bonardi, A., Bershadsky, J. (2018) Personal characteristics and outcomes of individuals with developmental disabilities who need support for self‐injurious behaviour. Journal of Intellectual Disability Research

Hiersteiner, D., Bradley, V., Ne’eman, A., Bershadsky, J. & Bonardi, A. (2017) Putting the research in context: The life experience and outcomes of adults on the autism spectrum. Inclusion 5(1) 45-59

Butterworth, J., Hiersteiner, D., Engler, J., Bershadsky, J. & Bradley, V.. (2015) National Core Indicators©: Data on the current state of employment of adults with IDD and suggestions for policy development. Journal of Vocational Rehabilitation 42 209-220 DOI:10.3233/JVR-150741

Bershadsky, J., Hiersteiner, D., Fay, M.L., Bradley, V. (2014) Race/Ethnicity and the Use of Preventive Health Care Among Adults with Intellectual and Developmental Disabilities. Medical Care 52(10)Suppl 3. S25-S31

Book chapter that features NCI-IDD data

Bradley, V. J., Hiersteiner, D., Rotholz, D. A., & Li, H. (in press). What do US national data tell us about people with intellectual and developmental disabilities who self-injure? In E. E. Lloyd-Richardson, I. Baetens, & J. L. Whitlock (Eds.), Oxford Handbook of Nonsuicidal Self-Injury. Oxford University Press.